An organic small-molecule compound, an OLED and an organic light-emitting device having the same

Abstract

The application relates to the technical field of organic photoelectric material preparation, in particular to an organic small-molecule compound, an OLED (Organic Light Emitting Diode) having the compound and an organic light-emitting device. The organic small-molecule compound is used as a material for constituting a light-emitting auxiliary layer by substituting and matching a dibenzo heterocycle on a triarylamine compound to manufacture an organic EL element, facilitates smooth implementation of an evaporation process of a device, effectively improves the light-emitting efficiency of the organic light-emitting device, and has a good application prospect.

Description

Technical Field

[0001] This invention relates to the field of organic optoelectronic material preparation technology, specifically to an organic small molecule compound, an OLED having the compound, and an organic light-emitting device. Background Technology

[0002] Organic light-emitting diodes (OLEDs), also known as organic light-emitting devices, are a technology that converts electrical energy into light energy through organic light-emitting materials. This technology involves applying voltage to an organic light-emitting element to inject holes from the anode and electrons from the cathode into the light-emitting layer. The injected holes and electrons then recombine to form excitons, causing light to be emitted.

[0003] Triarylamines are often used as auxiliary light-emitting layer materials due to their high hole mobility. However, few existing materials can form auxiliary light-emitting layers with excellent device performance, resulting in limited improvements in OLED lifetime and luminous efficiency. Some materials exhibit insufficient chemical stability and mechanical properties under long-term use or specific environments, leading to performance degradation such as color shift and ghosting. Furthermore, the energy level matching between the auxiliary light-emitting layer and adjacent functional layers formed by existing materials is not optimal, affecting carrier transport and recombination efficiency, and consequently impacting device performance.

[0004] Therefore, it is necessary to develop organic optoelectronic materials with good stability and energy level matching, and to find suitable OLED optoelectronic functional materials for OLED devices to solve the above problems. Summary of the Invention

[0005] To address the aforementioned technical problems, this invention provides an organic small molecule compound, an OLED incorporating the compound, and an organic light-emitting device. The provided organic small molecule compound exhibits good stability and can better match the energy levels between adjacent functional layers, enabling the device to achieve high current efficiency.

[0006] The organic small molecule compound provided by this invention is achieved through the following technical solution:

[0007] An organic small molecule compound having the structure shown in Formula I:

[0008] ;

[0009] In Formula I, L1-L3 are each independently selected from single bonds, phenylene, naphthylene, and biphenylene; Ar2 and Ar3 are each independently selected from any one or more combinations of phenyl, biphenyl, terphenyl, naphthyl, dibenzofuranyl, phenyl-substituted naphthyl, and naphthyl-substituted phenyl; Ar1 ​​is selected from the structure of Formula II; in Formula II, X is selected from O or S atoms; R1-R8 are each independently selected from hydrogen, deuterium, and C6-C12 aryl; any one of R1-R4 is a connection site with L1 and at least one of R1-R8 is selected from C6-C12 aryl.

[0010] Preferably, the hydrogen atoms in Formula I may be partially or completely deuterated.

[0011] Preferably, each of R1-R8 is independently selected from one or more of hydrogen, deuterium, phenyl, and naphthyl.

[0012] Preferably, one or two of R1-R8 are selected from phenyl.

[0013] Preferably, at least one of Ar2 and Ar3 contains a naphthyl group.

[0014] Preferably, formula II is selected from any of the following structures, wherein " "This is the connection point with Equation I:

[0015]

[0016] Preferably, the organic small molecule compound has the structure shown in any one of Formula I-1 to Formula I-4:

[0017]

[0018] In formulas I-1 to I-4, L1-L3 are each independently selected from single bonds, phenylene, naphthylene, and biphenylene; Ar2 and Ar3 are each independently selected from one or more of phenyl, biphenyl, terphenyl, naphthyl, dibenzofuranyl, phenyl-substituted naphthyl, and naphthyl-substituted phenyl; X is selected from O or S atoms; at least one of R1-R8 is selected from phenyl or naphthyl; the others are selected from hydrogen and deuterium.

[0019] More preferably, in formulas I-1 to I-4, one or two of R1-R8 are selected from phenyl or naphthyl; the others are selected from hydrogen or deuterium.

[0020] According to one or more embodiments, the present invention provides an organic small molecule compound selected from any of the following chemical structures:

[0021]

[0022] The present invention also provides an application of the organic small molecule compound described above in an organic electroluminescent device.

[0023] The present invention also provides an organic electroluminescent device, the organic electroluminescent device comprising:

[0024] Substrate layer;

[0025] A first electrode is located on the substrate;

[0026] An organic light-emitting functional layer is disposed on the first electrode;

[0027] The second electrode is located on the organic light-emitting functional layer;

[0028] The organic light-emitting functional layer includes a light-emitting auxiliary layer, which contains the aforementioned small organic molecule compounds.

[0029] The present invention also provides a composition comprising an organic small molecule compound as described in formula (I).

[0030] The present invention also provides a formulation comprising an organic small molecule compound with the structure shown in formula (I) above, or a composition as described above, and at least one solvent. The solvent is not particularly limited and may be any solvent well known to those skilled in the art, such as unsaturated hydrocarbon solvents like toluene, xylene, mesitylene, tetrahydronaphthalene, decahydronaphthalene, dicyclohexane, n-butylbenzene, sec-butylbenzene, tert-butylbenzene, carbon tetrachloride, chloroform, dichloromethane, dichloroethane, chlorobutane, bromobutane, chloropentane, bromopentane, chlorohexane, bromohexane, chlorocyclohexane, bromocyclohexane, etc.; halogenated unsaturated hydrocarbon solvents like chlorobenzene, dichlorobenzene, trichlorobenzene, etc.; ether solvents like tetrahydrofuran, tetrahydropyran, etc.; and ester solvents like alkyl benzoates.

[0031] The organic electroluminescent device of the present invention can be used in OLED lighting or display devices.

[0032] The present invention also provides a display or lighting device comprising one or more of the organic electroluminescent devices described above.

[0033] In summary, compared with the prior art, the present invention has the following beneficial effects:

[0034] The organic small molecule compound of the present invention is a triaryl compound obtained by combining an aryl-substituted dibenzoheterocyclic group with a defined group. The compound has excellent luminescence efficiency and good stability. At the same time, the material provided by the present invention can be used in devices to effectively cooperate with other layer materials of the device for transmission and light emission, thereby improving the luminescence efficiency of organic light-emitting devices. Detailed Implementation

[0035] The technical solutions of the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present invention.

[0036] Throughout this specification, unless explicitly stated otherwise, the term "including" any component will be understood to imply the inclusion of other components, not to exclude any other components. Furthermore, it should be understood that throughout this specification, when an element such as a layer, film, region, or substrate is referred to as being "on" or "above" another element, it may be "directly on" the other element, or there may be intermediate elements present. Additionally, "on" or "above" means located above the target portion, and not necessarily above it in the direction of gravity.

[0037] One object of the present invention is to provide an electroluminescent device, the organic electroluminescent device comprising: a substrate layer; a first electrode on the substrate; an organic light-emitting functional layer on the first electrode; a second electrode on the organic light-emitting functional layer; the organic light-emitting functional layer comprising a light-emitting auxiliary layer; the light-emitting auxiliary layer comprising an organic small molecule compound represented by Formula I.

[0038] In one embodiment of the present invention, the light-emitting auxiliary layer in an organic electroluminescent (OLED) device comprises one or more components of the compounds shown in the above general formula I as light-emitting auxiliary materials.

[0039] In a preferred embodiment of the present invention, an OLED is provided, comprising a substrate, an anode, a cathode, an organic light-emitting functional layer, and a capping layer. The organic light-emitting functional layer may include a light-emitting layer, a light-emitting auxiliary layer, a hole transport layer, a hole injection layer, an electron transport layer, an electron injection layer, etc., or may only include a light-emitting layer and one or more other layers. The light-emitting auxiliary layer comprises one or more components of the compounds shown in the above-described general formula I. Optionally, a capping layer, a protective layer, and / or an encapsulation layer are further provided above the cathode.

[0040] The substrate described in this invention can be any substrate typically used in organic light-emitting devices. It can be a glass or transparent plastic substrate, an opaque material such as silicon or stainless steel, or a flexible PI film. Different substrates have different mechanical strengths, thermal stability, transparency, surface smoothness, and water resistance, and their applications vary depending on their properties.

[0041] As for the materials used in the hole injection layer, hole transport layer, electron transport layer, and electron injection layer, any material can be selected from known materials used in OLED devices.

[0042] As a host-guest material capable of generating blue, green, and blue-green fluorescence, it not only needs to possess extremely high fluorescence quantum luminescence efficiency but also needs to have an appropriate energy level.

[0043] The present invention will now be described in detail with reference to specific embodiments. Unless otherwise specified, all raw materials and solvents used in the synthesis embodiments are commercially available, and the solvents were used directly without further processing.

[0044] Example

[0045] Example 1: Synthesis of Compound 27

[0046] Synthesis route:

[0047]

[0048] Synthesis method:

[0049] 1) Add 600 mL of a mixed solution of SM1 (1 mmol), SM2 (1.1 mmol), Pd(dppf)Cl2 (0.05 mmol), potassium carbonate (3 mmol), and THF / H2O (THF / H2O volume ratio 2:1) to a 1.0 L reaction flask. Start stirring, purge with nitrogen, and allow the reaction flask temperature to rise to 60 °C for 3 h. After the reaction is complete, cool to room temperature, pour the solution from the reaction flask into a 1.0 L separatory funnel, allow it to stand and separate into layers, separate the aqueous phase, transfer the organic phase to a 1.0 L single-necked flask, concentrate under reduced pressure, slurry, filter, and dry to obtain a white solid S1.

[0050] 2) Add 600 mL of a mixed solution of S1 (1 mmol), SM3 (1.1 mmol), Pd(dppf)Cl2 (0.05 mmol), potassium carbonate (3 mmol), and THF / H2O (THF / H2O volume ratio 2:1) to a 1.0 L reaction flask. Start stirring, purge with nitrogen, and allow the reaction flask temperature to rise to 60 °C for 3 h. After the reaction is complete, cool to room temperature, pour the solution from the reaction flask into a 1.0 L separatory funnel, allow it to stand and separate into layers, separate the aqueous phase, transfer the organic phase to a 1.0 L single-necked flask, concentrate under reduced pressure, slurry, filter, and dry to obtain a white solid S2.

[0051] 3) Add S2 (1 mmol), SM4 (1.1 mmol), Pd2dba3 (0.05 mmol), X-PHOS (0.1 mmol), sodium tert-butoxide (3 mmol), and toluene (300 mL) to a 500 mL reaction flask, then purge with nitrogen, turn on the stirrer, heat the three-necked flask to 80 °C, and react for 2 h. After the reaction is complete, cool to room temperature, stir with 100 mL of water, filter, wash with 100 mL of petroleum ether, slurry, filter again, and dry to obtain a white solid S3.

[0052] 4) Add S3 (1 mmol), SM5 (1.1 mmol), Pd2dba3 (0.05 mmol), X-PHOS (0.1 mmol), sodium tert-butoxide (3 mmol), and toluene (300 mL) to a 500 mL reaction flask, then purge with nitrogen, turn on the stirrer, heat the three-necked flask to 80 °C, and react for 2 h. After the reaction is complete, cool to room temperature, stir with 100 mL of water, filter, wash with 100 mL of petroleum ether, slurry, filter again, and dry to obtain the final product compound 27.

[0053] Analysis by liquid chromatography-mass spectrometry yielded the following LC-MS (m / z) values: theoretical value 815.32, measured value 815.84.

[0054] Example 2: Synthesis of Compound 1

[0055] Following the synthesis steps and reaction conditions of Example 1, compound 1 was synthesized. The LC-MS (m / z) values ​​obtained by liquid chromatography-mass spectrometry were 639.26 and 639.64, respectively.

[0056] Example 3: Synthesis of Compound 8

[0057] Following the synthesis steps and reaction conditions of Example 1, compound 8 was synthesized. The LC-MS (m / z) values ​​obtained by liquid chromatography-mass spectrometry were 779.28 and 779.82, respectively.

[0058] Example 4: Synthesis of Compound 10

[0059] Following the synthesis steps and reaction conditions of Example 1, compound 10 was synthesized. The LC-MS (m / z) values ​​obtained by liquid chromatography-mass spectrometry were 689.27 and 689.75, respectively.

[0060] Example 5: Synthesis of Compound 15

[0061] Following the synthesis steps and reaction conditions of Example 1, compound 15 was synthesized. The LC-MS (m / z) values ​​obtained by liquid chromatography-mass spectrometry were 815.32 and 815.84, respectively.

[0062] Example 6: Synthesis of Compound 20

[0063] Following the synthesis steps and reaction conditions of Example 1, compound 20 was synthesized. The LC-MS (m / z) values ​​obtained by liquid chromatography-mass spectrometry were 815.32 and 815.86, respectively.

[0064] Example 7: Synthesis of Compound 26

[0065] Following the synthesis steps and reaction conditions of Example 1, compound 26 was synthesized. The LC-MS (m / z) values ​​obtained by liquid chromatography-mass spectrometry were 815.32 and 815.82, respectively.

[0066] Example 8: Synthesis of Compound 33

[0067] Following the synthesis steps and reaction conditions of Example 1, compound 33 was synthesized. LC-MS analysis using liquid chromatography-mass spectrometry yielded a theoretical value of 765.30 and a measured value of 765.88 (m / z).

[0068] Example 9: Synthesis of Compound 40

[0069] Following the synthesis steps and reaction conditions of Example 1, compound 40 was synthesized. The LC-MS (m / z) values ​​obtained by liquid chromatography-mass spectrometry were 815.32 and 815.86, respectively.

[0070] Example 10: Synthesis of Compound 50

[0071] Following the synthesis steps and reaction conditions of Example 1, compound 50 was synthesized. LC-MS analysis using liquid chromatography-mass spectrometry yielded a theoretical value of 689.27 and a measured value of 689.78 (m / z).

[0072] Example 11: Synthesis of Compound 60

[0073] Following the synthesis steps and reaction conditions of Example 1, compound 60 was synthesized. LC-MS analysis using liquid chromatography-mass spectrometry yielded a theoretical value of 815.32 and a measured value of 815.90 (m / z).

[0074] Example 12: Synthesis of Compound 61

[0075] Following the synthesis steps and reaction conditions of Example 1, compound 61 was synthesized. LC-MS analysis using liquid chromatography-mass spectrometry yielded a theoretical value of 729.27 and a measured value of 729.76 (m / z).

[0076] Example 13: Synthesis of Compound 64

[0077] Following the synthesis steps and reaction conditions of Example 1, compound 64 was synthesized. LC-MS analysis using liquid chromatography-mass spectrometry yielded a theoretical value of 805.30 and a measured value of 805.84 (m / z).

[0078] Example 14: Synthesis of Compound 73

[0079] Following the synthesis steps and reaction conditions of Example 1, compound 73 was synthesized. LC-MS analysis using liquid chromatography-mass spectrometry yielded a theoretical value of 791.32 and a measured value of 791.92 (m / z).

[0080] Example 15: Synthesis of Compound 87

[0081] Following the synthesis steps and reaction conditions of Example 1, compound 87 was synthesized. LC-MS analysis using liquid chromatography-mass spectrometry yielded a theoretical value of 815.32 and a measured value of 815.78 (m / z).

[0082] Example 16: Synthesis of Compound 103

[0083] Following the synthesis steps and reaction conditions of Example 1, compound 103 was synthesized. LC-MS analysis using liquid chromatography-mass spectrometry yielded a theoretical value of 833.43 and a measured value of 833.97 (m / z).

[0084] Example 17: Synthesis of Compound 148

[0085] Following the synthesis steps and reaction conditions of Example 1, compound 148 was synthesized. LC-MS analysis using liquid chromatography-mass spectrometry yielded a theoretical value of 838.46 and a measured value of 838.98 (m / z).

[0086] Example 18: Synthesis of Compound 149

[0087] Following the synthesis steps and reaction conditions of Example 1, compound 149 was synthesized. LC-MS analysis using liquid chromatography-mass spectrometry yielded a theoretical value of 831.30 and a measured value of 831.94 (m / z).

[0088] Example 19: Synthesis of Compound 150

[0089] Following the synthesis steps and reaction conditions of Example 1, compound 150 was synthesized. LC-MS analysis using liquid chromatography-mass spectrometry yielded a theoretical value of 745.24 and a measured value of 745.86 (m / z).

[0090] Example 20: Synthesis of Compound 151

[0091] Following the synthesis steps and reaction conditions of Example 1, compound 151 was synthesized. LC-MS analysis using liquid chromatography-mass spectrometry yielded a theoretical value of 807.30 and a measured value of 807.96 (m / z).

[0092] Example 21: Synthesis of Compound 152

[0093] Following the synthesis steps and reaction conditions of Example 1, compound 152 was synthesized. LC-MS analysis using liquid chromatography-mass spectrometry yielded a theoretical value of 831.30 and a measured value of 831.88 (m / z).

[0094] The following are several examples of applications of the luminescent auxiliary materials described in this invention in OLED devices to further illustrate the beneficial effects of the compounds of this invention. The materials used in the examples were either commercially available or synthesized in-house.

[0095] Manufacturing of OLED devices:

[0096] As a reference fabrication method for one embodiment of the device, the present invention involves depositing 50-500 nm of ITO / Ag / ITO (ITO:Ag:ITO weight ratio of 1:(10-20):1) as an anode on an alkali-free glass substrate. On the anode, a hole injection layer (5-20 nm), a hole transport layer (50-120 nm), a light-emitting auxiliary layer (5-120 nm), a light-emitting layer (body material: doped material, doped material weight percentage 0.5%-10%, 20-50 nm), a hole blocking layer (5-20 nm), an electron transport layer (20-80 nm), and an electron injection layer (0.5-10 nm) are sequentially deposited. Then, Mg and Ag (weight ratio 1:9, 10-50 nm) are co-deposited to form a semi-transparent cathode, followed by the deposition of a capping compound (50-90 nm). Finally, the light-emitting device is encapsulated using epoxy resin adhesive under a nitrogen atmosphere.

[0097] In a preferred embodiment, the OLED device provided by the present invention has the following structure: first, an alkali-free glass substrate is washed with isopropanol for 15 minutes using an ultrasonic cleaner, and then subjected to UV ozone washing treatment in the air for 30 minutes. The prepared substrate was deposited using a vacuum evaporation method. First, an ITO / Ag / ITO mixture (ITO:Ag:ITO weight ratio of 1:10:1, 120 nm) was deposited as the anode. Then, a hole injection layer (HT:PD weight ratio = 98:2, 10 nm), a hole transport layer (HT, 100 nm), a light-emitting auxiliary layer (compound 27, 5 nm), a light-emitting layer (body material BH:doped material BD weight ratio = 97:3, 30 nm), a hole blocking layer (HB, 5 nm), an electron transport layer (ET:Liq = 1:1, 30 nm), and an electron injection layer (LiF, 0.5 nm) were deposited sequentially. Mg and Ag (weight ratio 1:9, 10 nm) were then co-deposited to form a semi-transparent cathode. Finally, a compound CPL (65 nm) was deposited as a capping layer. This is referred to as Application Example 1.

[0098] It should be noted that the materials used in this application example are merely exemplary and do not constitute a specific limitation of the application of the light-emitting auxiliary layer material in the device. Known or unknown materials can be selected for conventional substitution. The molecular structural formulas of the relevant materials are shown below (particularly preferred are those shown below, but this does not mean that the invention is limited to these structures):

[0099]

[0100] Application Examples 2-21 and Comparative Example 1 were prepared using the method described in Application Example 1 above, with the only difference being that compounds listed in Table 1 were used as luminescent auxiliary materials instead of compound 27 in Application Example 1. The structure of Ref-1 used in Comparative Example 1 is as follows: .

[0101] Performance evaluation of OLED devices:

[0102] The current of the OLED device at different voltages was measured using a Keithley 2365A digital nanovoltmeter, and then the current density of the OLED device at different voltages was obtained by dividing the current by the emitting area. The brightness and radiant energy flux density of the OLED device at different voltages were measured using a Konicaminolta CS-2000 spectroradiometer. Based on the current density and brightness of the OLED device at different voltages, the current density (10 mA / cm²) at the same voltage was obtained. 2 The operating voltage (Volt) and current efficiency (cd / A) are given by BI = E / CIEy, which refers to the Blue Index in blue light and is also a parameter measuring the luminous efficiency of blue light. E refers to the current efficiency, and CIEy refers to the ordinate color point obtained by substituting the wavelength of the device's emission half-peak into the CIE1930 software. The test data are shown in Table 1.

[0103] Table 1. Examples of Applications and Electroluminescence Properties of Luminescent Auxiliary Layer Materials

[0104]

[0105] As shown in Table 1, compared with Comparative Example 1, the compounds of this application, based on the Ref-1 structure, are modified by substituting dibenzofuranyl or dibenzothiopheneyl, and combined with specific aryl and heteroaryl groups, which can better achieve the balance of electron and hole transport and exciton conversion rate, thereby improving the luminous efficiency of the device by 10% and reducing the power consumption of the device.

[0106] This specific embodiment is merely an explanation of the present invention and is not intended to limit the invention. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they are within the scope of the claims of the present invention.

Claims

1. An organic small molecule compound, characterized in that, Selected from any of the following chemical structures:

2. The application of the organic small molecule compound according to claim 1 in the preparation of organic electroluminescent devices.

3. An organic electroluminescent device, characterized in that, The organic electroluminescent device includes: Substrate layer; A first electrode is located on the substrate; An organic light-emitting functional layer is disposed on the first electrode; The second electrode is located on the organic light-emitting functional layer; The organic light-emitting functional layer includes a light-emitting auxiliary layer, which contains the organic small molecule compound as described in claim 1.

4. A composition, characterized in that, The composition comprises the small organic molecule compound as described in claim 1.

5. A formulation, characterized in that, The formulation comprises an organic small molecule compound as described in claim 1 or a composition as described in claim 4 and at least one solvent.

6. A display or lighting device, characterized in that, The device includes the organic electroluminescent device as described in claim 3.

Images